Lemelson
composite filaments



Oct. 14, 1969 J LEMELSON Re. 26,688

COMPOSITE FILAMENTS Original Filed March 15, 1965 2 Sheets-Sheet 1VIIIIIIIIIIIIIII INVENTOR. Jerome HLemelson Oct. 14, 1969 J LEMELSON Re.26,688

COMPOSITE FILAMENTS Original Filed March 15. 1965 2 Sheets-Sheet 2INVENTOR. Jerome H.Lemelson United States Patent 0 26,688 COMPOSITEFILAMENTS Jerome H. Lemelson, 85 Rector St., Metuchen,N.J. 08840Original No. 3,327,339, dated June 27, 1967, Ser. No.

439,529, Mar. 15, 1965. Application for reissue June 17, 1968, Ser. No.741,817

Int. Cl. A46d l/OO; Dllld 11/06 US. Cl. 15-209 5 Claims Matter enclosedin heavy brackets appears in the original patent but forms no part ofthis reissue specification; matter printed in italics indicates theadditions made by reissue.

ABSTRACT OF THE DISCLOSURE Composite, elongated, plastic elements areprovided which are extruded of a plurality of rhflerent polymericmaterials, one on the other. Each extrusion has a core portion which issurrounded by a jacket bonded thereto along its length. Both the jacketand core portions are extruded of polymeric materials, with the jacketportion being more flexible than the core portion. The jacket may alsobe a cellular polymeric material surrounding either a core which issolid through and through or a hollow tube permitting the conduction offluid therethrough.

This invention relates to synthetic plastic filaments and is acontinuation-in-part of application Ser. No. 239,036 filed Oct. 20,1962, and now abandoned, for Cleaning Element and Method. In particular,this invention is concerned with plastic filaments formed by extruding aplurality of polymers, one over the other and each imparting a differentuseful characteristic to the composite filament.

It is known in the art to extrude or otherwise form filaments of thevarious synthetic plastic resins for various uses. Flexible formulationsof such synthetic plastics as polyvinylchloride, polyethylene,polypropylene, and polyamide resins have been extruded or spun intofibers or filaments which have been woven into flexible Webs and used ascloth or have been twisted into cord, rope and the like. Rigidformulations of polyamides, polystyrene, polyesters and the like havebeen applied primarily as bristles in the fabrication of brushes.However, when utilized as bristles in the fabrication of brushes andbrushing devices, many of the rigid plastics suffer a number ofshortcomings which limit their application and life. For example,bristles made of rigid plastic may be subject to permanent set ordeformation when deflected during certain types of application or use,thereby resulting in a brushing article which soon loses its utility.Attrition on the bristles due to the abrasion of small particles mayalso lessen its utility. More important, the physical characteristics ofthe rigid plastic itself may limit its application. For example, whileit may be desired to sweep a surface in the act of removing dirttherefrom, the rigid bristles may easily scratch or mar the surface.Most brush bristles made of synthetic plastic, are fabricated by shearcutting elongated plastic filaments to short lengths. Inherent in thecutting are sharp edges provided at both ends of the cut lengthsthereof. Such sharp edges tend to scratch and cut most surfaces againstwhich the bristles are brought to bear. Utilization of a softer or moreflexible plastic will provide a bristle which does not have thestiffness necessary to perform brushing and cleaning functionseffectively. While certain bristle structures have been taught in theprior art which employ a metal wire as a core, such filaments suffer anumber of shortcomings for many uses and their applications arecorrespondingly limited. Metal, being substantially harder than plastic,will easily scratch most surfaces and when lengths of such metal wirefilaments are cut and used, the outer sheathing soon wears off exposingthe metal core which may easily scratch the surface to which thefilaments are applied. Threads and other flexible cores have beenutilized but these lack sufflcient rigidity to permit the necessarywiring action. Accordingly, it is a primary object of this id vention toprovide a new and improved synthetic bristle. Another object is toprovide a new and improved synthetic filament utilizablc for bristlesand the like and having substantially the rigidity of a conventionalfilament made of rigid plastic yet being substantially free of sharpedges which will scratch or mar surfaces against which they are brought.

Another object is to provide an improved filament producible by theextrusion of flexible and rigid plastics and having the characteristicsof each applied to advantage in the composite structure.

Another object is to provide a composite extrusion having separatelongitudinal flexible and rigid portions joined by the commingling ofthe material of each with each of said portions being fabricated byextruding compatible flexible and rigid formulations of the samepolymer, one on the other, so as to define an improved structure free ofthe degrading effects often experienced when different polymers arebrought into abutment with each other or united.

Another object is to provide a composite filament having a rigid coreand a flexible sheaving cooperating to enhance the use of the filament.

Another object is to provide a new and improved filament for use inbrushes and the like and having a tip which is rounded and free of sharpedges which would ordinarily scratch surfaces against which the brushmade thereof may be brought to bear against.

Another object is to provide a composite filament for use in brushes andthe like and having a relatively soft tip which may gently wipe thesurface it is brought to bear against, said filament having a firmstructure with substantially the rigidity of conventional bristles.

Another object is to provide an improved structure in a composite wipingmaterial at least a portion of which is made of flexible cellularplastic expanded in situ on a base.

With the above and such other objects in view as may hereinafter morefully appear, the invention consists of the novel constructions,combinations and arrangements of parts as will be more fully describedand illustrated in the accompanying drawings but it is to be understoodthat changes, variations and modifications may be resorted to which fallWithin the scope of the invention as claimed.

There is shown in FIGS. 1 and 2 an extruded or other- Wise formedfilament element which may be used for various cleaning. polishing orwiping purposes to be described hereafter. The element 10, if producedby extrusion, is elongated in shape and has a constant cross section. Itcomprises a core element 12 of a first material which is surrounded by ajacket or layer of a second material 14 illustrated as a flexible,cellular plastic such as cellular polyvinyl chloride, cellulose acetate,urethane or the like. In a preferred form of the invention the core 12is made of a more rigid plastic than that comprising the jacket orcovering 14, and may comprise the more rigid formulations of polyvinylchloride, polystyrene, polyethylene, polypropylene or the like. In apreferred method of fabricating the composite filament, both the core 12and the jacket 14 may be simultaneously extruded to form the singleelement 10 in a process whereby at least one of the two materials isintroduced against the other while in a Q semi-molten condition suchthat, when it solidifies, it will molecularly bond to or become integralwith the other by welding or heat fusion.

The cleaning element illustrated in FIGS. 1 and 2 may also be fabricatedby dipping the core element 12 into a container of a solution or moltenquantity of the material of which the jacket or coating 14 is made andthereafter removing 12 with the material 14 coated thereon.Subsequently, the coating 14 may be foamed by heating or furtherprocessing or may contain a foaming or blowing agent operative to expandsame in situ on core 12.

In application of the structure illustrated in FIGS. 1 and 2 as acleaning element the core element 12 serves as a stiffener or mainsupport for the filament 10 while the jacket 14 provides a softer andmore flexible surface which may be used for wiping, buffing or cleaningfunctions without marring or scratching the surface of the workpiece, acondition which may exist if. said surface were engaged by the coreelement 12 per se.

Notation refers to the interface between 12 and 14 which interface maynot discernibly exist if both the core 12 and jacket 14 aresimultaneously extruded of thermoplastic materials. The end 13 of 12 isillustrated as being rounded and surrounded by material 14' which is anextension of the covering or jacket material 14 surrounding core 12.

For many brushing and wiping operations, a conven tional syntheticbristle. utilized in an array of same defining a brushing surface, isrelatively abrasive to the work surface engaged thereby. This is due tothe fact that the conventional self-supporting bristle is formed of arelatively rigid plastic by the continuous extrusion of said plasticinto a filament or filaments and the individual brush bristles are cuttherefrom by the shearing action of a blade such as a rotary cutter.Regardless of the angle at which the cutter shears lengths of bristlesoff the longer extruded filament, inherent in the shearing action is thedevelopment of sharp edges at each end of the cut lengths of filament.When assembled and secured in an array to a base to define multiple rowsof filaments. such a multitude of sharpedged members are operative toscratch. cut or tear material against which the brush is brought tobear. For many brushing applications, it may be desirable to derive thewiping or polishing action of individual stiff bristles without theinherent scratching, cutting or tearing action created by the sharpedges of the bristle. For example. in cleaning teeth. bristles cut fromrelatively rigid plastics may easily irritate or cut the gums.

The jacket material 14 of the filament structure of. FIG. 2 may also bemade of a non-cellular plastic more flexible than the material of thecore 12. Similarly, the rounded end 13 of core filament 12 permits useof said core filament as a bristle per se for many brush applications asit is void of sharp edges.

The filament structures illustrated in FIGS. 1 to 4 are operative toprovide many of the beneficial features found in stiff or rigid brushingelements or bristles without the mentioned disadvantages inherent inshear cut filaments or bristles fabricated of rigid plastics. This isaccomplished by fabricating the filament to be cut to define individualbristles. each having a core of rigid plastic and having a more flexibleplastic as a sheaving formed in situ on the core along the entire lengthof the bristle. Thus, regardless of the angle at which the shearing cutis made to sever individual bristle elements from the main extrusion,there will always be provided flexible sheaving material outward of themore rigid core which Will serve as a buffer or cushion materialcompressively engaged against the surface being wiped by the more rigidcore but protecting said surface from direct engagement by said core.Core element 12 may also etxend completely to the end of the jacket 14as illustrated in FIG. 4, depending on the intended application of saidelement.

In FIG. I is shown a modified form of the composite p... ti)

extrusion shown in FIG. 1 having a flexible, cellular platstic jacket orcovering 14 surrounding a core element 12' which is a hollow tubularextrusion of a polymeric marerial such as those hereinbefore described.T he core portion 12' thus may be utilized for conducting or deliveringa fluid through the passageway in the tubular portion 12' of thecomposite extrusion.

If the material comprising the jacket 14 were to be utilized for theentire wiping element 10, it would not have sufficient rigidity orinternal support to properly effect many cleaning operations. Thestiffened internal support or core 12 serves as means for retaining theelement in a predetermined upstanding shape and for transmitting orimparting forces to the sheaving 14 and imparted to said core from abase to which the element 10 is secured so as to brush or wipe thesurface being engaged thereby.

FIGS. 3 and 4 illustrate another form of this invention defining anelongated element 20 which comprises a core 22 made of a first and morerigid material than a surrounding sheaving or jacket 24. The jacket ispreferably made of a flexible thermoplastic material but is unlike thecore material comprising of FIGS. 1 and 2 that it is not porous orcellular. Materials of which the core 22 may be made may comprise arigid or semi-rigid vinyl, polyethylene or the like while the coveringor jacket 24 may comprise a more flexible formulation of the same orother compatible thermoplastic material comprising the core. The member22 is preferably formed by simultaneously extruding both core and jacketas a unitary rod or filament and may serve many of the functionshereinabove described for the member 10 such as buffing, wiping,polishing or the like wherein the flexible jacket 24 serves as ayieldable medium and the more rigid core 22 serves as means forstiffening or rigidizing the assembly 20 so that a force applied to thatend of element 20 which is secured to a base member will be transmittedalong the length thereof to the surface of a workpiece withoutsubstantial loss. It is obvious that-if the entire member 20 were madeof a flexible plastic material such as that comprising the covering orcoating 24, it would merely deflect against a surface to be cleaned,buffed or wiped thereby without the application of sufficient force tobe as effective in such action as when provided with the stiffer coremember or portion 22. As in the case of the element of FIG. 1, thestructure illustrated in FIGS. 3 and 4 may be fabricated bysimultaneously extruding both materials or extruding and forming thecore member 22 first and continuously feeding it to means for extrudingthe outer jacket 24 thereon.

Notation 22 refers to the end face of the core element 22 which isformed when the member 20 is sheared to length. Notation 22" refers toone of the circular sharp edges at the end of core element 22 formedwhen the cut is made. It is seen that the end portion 24' of sheaving 24serves as means for preventing edge 22" from normally engaging thesurface of a work member when element 20 is laterally moved across saidwork surface as in most brushing functions. Rather, the edge 24" ofsheaving 24 is first brought against the work surface during thebrushing action. Since the material comprising sheaving 24 is relativelymore flexible than that of which core 22 is made, a non-abrading wipingor brushing action is attained and the material at the end of sheaving24 will be compressively deflected against the work surface to preventthe sharp edge 22" of core material 22 from scratching or cutting theWork surface.

If the core members 12 or 22 are provided as hollow, tubular extrusions,they may be utilized for delivering various fluid materials through thecleaning or wiping members from the base to which they are secured tothe surface of the workpiece. For example, if the device is utilized asa waxing means, solutions of various waxes or liquid wax may bedelivered through such a hollow tubular core by centrifugal force and/orpressurizing the source of the supply of the wax material.

Many dissimilar polymers have corrosive effects on one another. Vinyls,for example, are not compatible with many other polymers. Polyethylenesand polypropylenes are not easily welded or bonded to other polymers. Ihave discovered that most suitable combinations of which to produce thecomposite filament structures of FIGS. 1 to 4 are rigid and flexibleformulations of the same polymer such as plasticized and unplasticizedvinyl, high and low density polyethylene or polypropylenes. Suchcombinations are not only compatible with each other but form compositearticles by extrusion which exhibit little or no interfacialdegradation, may have substantially the same melting points and easilyunite in molecular bonds when brought together.

In another form of the invention the structures illustrated in FIGS. 1to 3 may represent improved textile fibers or filaments capable of beingwoven into cloth for wearing apparel and other fabrics. For example,FIG. 1 may represent a textile filament comprising a core 12 made ofeither a single mono-filament or a fine thread of any suitable organicor synthetic plastic material or glass fiber or fibers surrounded by thefoam jacket 14 of expanded cellular plastic. The jacket 14 preferablycomprises the major portion of the filament and is in the order of .005to .030" or greater in outside diameter while the core element or thread12 may be in the order of .010" in diameter or less. The jacket 14 maycomprise foamed or expanded vinyl, urethane acetate or the like whilethe core member 12 is preferably a synthetic textile filament or yarnsuch as nylon, Dacron, rayon, Orlon, polypropylene or glass havingsubstantially greater tensile strength than the tubular formation 14which surrounds it and thereby provides a composite article 10 ofsuperior strength characteristics, which may be woven into variousfabric formations. The article 10 may be produced by extruding orotherwise providing th core member 12 as a continuous filament or threadand extruding thereover the molten resin comprising the jacket 14, inthe presence of a foaming agent that is gaseous at the extrusiontemperature whereby said resin immediately foams or expands into acellular plastic as or shortly after it is coated onto 12.

The resulting composite article 10 possesses the softness, flexibilityand insulating characteristics of the cellular plastic and the tensilestrength of the flexible filament or thread core 12.

In FIG. 5 is shown a cleaning device employing a plurality of compositefilaments 10 or 20 secured to a base 25 which is illustrated as a drumand is rotatable on a shaft or axle 26 which is supported by a base orframe 27 in a manner to permit rotation of the drum 25. Drive means forthe drum assembly 25 (not shown) may be provided including a motor forrotating said drum at constant speed. The drum assembly is shownpositioned adjacent a workpiece W so that the elongated filaments orwiping elements 10 compressively engage the surface of W as drum 25rotates and are urged thereagainst as a result of the semi-rigidassembly of the individual elements 10 and the drum 25 whereby thestiffened or rigidized core of each element is used as a means fordirecting and compressively engaging the element against the outersurface of W. The base 25, of course, may have any suitable shape.Fastening of one or a plurality of the wiping elements 10 may beprovided as illustrated in my application Ser. No. 477,467 or by anysuitable means.

FIG. 6 illustrates structural details of a cleaning and wiping elementin the form of a sheet, the major portion of which comprises a flexible,synthetic cellular plastic material. The cleaning element 30, a fragmentof which is shown in cross section, comprises a layer or sheet 31 ofexpanded, cellular plastic such as cellular cellulose acetate, celluarpolyurethane, cellular flexible polyvinyl chloride or other suitablesynthetic sponge-like cellular material. Bonded or mechanically securedto one side or face of the cellular plastic member 31 is a sheet 32 ofwoven material such as cloth, canvas, netting or the lik and made up ofa plurality of threads or filaments of textile material woven into acloth or sheet.

The cleaning member 30 may be produced in a number of manners dependingon the desired end product. For example, both the sheets 31 and 32 maybe provided as separate, preformed webs which may be conveyed orotherwise positioned into facial contact with each other after theapplication of a suitable adhesive to either or both abutting surfaceswhereby the two will become adhesively bonded together.

In another method of fabricating the combined cleaning element 30 ofFIG. 6, the plastic material which eventually comprises the layer 31 ofcellular plastic, is extruded or otherwise applied onto the uppersurface of 32 and blown or foamed thereon to form a substantiallyuniform layer. By this method, the cellular plastic, while still in aliquid, unfoamed state, may be made to penetrate the spaces between thethreads or filaments of the cloth base 32 so that, upon foaming andsolidification, said layer 31 will extend into and preferably throughthe cloth 32 resulting in a mechanical assembly of the two. If theplastic comprising layer 31 is such that it possesses adhesivecharacteristics when in contact with the individual thread or filamentelements of the cloth or canvas 32, the combined mechanical and adhesiveassembly means will provide a superior fastening assembly in which thetwo layers are substantially integral with each other and may not beeasily torn apart or separated. The superior strength afforded by thetextile webbing or canvas base will permit the utilization of the spongesheeting in many applications where the cellular plastic layer would notbe applicable per se. In particular, the combined cleaning article orweb 30 may be ap lied where it may be subjected to tensile forces whichwould ordinarily tear the relatively weaker, unsupported cellularplastic sheeting. The article or sheet 30 may be utilized, for example,as a bufling belt, wiping and polishing cloth, etc.

Other applications for the combined sheeting illustrated in FIG. 6include various articles of manufacture made thereof or in combinationwith other materials.

I claim:

1. An article of manufacture for use as a cleaning and wiping elementwith a plurality of similar elements comprising an elongated, flexiblefilament made of a plurality of synthetic polymeric materials, saidfilament having a core portion made of a first polymeric material andsurrounded by a jacket portion, the material comprising said jacketbeing a flexible, synthetic plastic supported along substantially thelength of said element by said core and integrally bonded thereto, saidcore being of a more rigid polymeric material than said jacket, thematerial of said jacket portion extending beyond one end of said coreportion and providing a flexible tip portion for said filament elementwhich may be used for wiping or bufling purposes.

2. An article of manufacture in accordance with claim 1, said flexibletip portion being rounded at its end.

3. An article of manufacture for use as a cleaning and wiping elementwith a plurality of similar elements comprising an elongated, flexiblefilament made of a plurality of synthetic polymeric materials, saidfilament having a core portion made of a first polymeric material andsurrounded by a jacket portion, the material comprising said jacketbeing a flexible, synthetic plastic supported along substantially thelength of said element by said core and integrally bonded thereto, saidcore being of a more rigid polymeric material than said jacket, thematerial comprising said jacket being an expanded, cellular syntheticplastic formed in situ on said more rigid core portion.

4. An article of manufacture comprising an elongarml flexible extrusionmode of a plurality of iryntheric polymeric materials, said extrusionhaving a tubular core portion made of a polymeric material and suroundedby a jacket portion, the material comprising said jacket being aflexible synthetic plastic supported along substantially the length ofsaid element by said core and integrally bonded thereto, said core beingmade of a more rigid polymeric material than said jacket, the materialcomprising said jacket being an expanded, cellular synthetic plasticformed in situ on said more rigid core portion.

5. An article of manufacture in accordance with claim 4 the materials ofsaid core and jacket portions comprising repectively rigid and flexibleformulations of the same polymer such as high and low densitypolyethylenes and polypropylenes and plasticized and unplasticizeilformulations of vinyl resins.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

8 UNITED STATES PATENTS Smith 138137 Aries 138137 Tatsch 138137Stevenson 57140 Staines 15230 X Heldt 15-179 Radford 15-230 Briggs 57153Wandelet a] 15-159.1 Politzer et a1 l5118 X Peterson 15159.1 X

Canada.

WALTER A. SCHEEL, Primary Examiner L. G. MACHLIN, Assistant Examiner US.Cl. X.R.

